[Solved]: USB extension cable voltage drop. What are my options?

[Abz Hussain]

Hi all, I have the following issue with USB with my PC and was after some possible solutions.
We have just had building works completed and a new study was made. Just for background information the computer is located 10m from my new desk and sitting position (Its just how it is with the room/size/location available).
My intention is to use the pc in the following way:
Run a 10m usb 2.0 extension lead from back of pc, in & around the trunking and into a usb 2.0 module which fits in the trunking and into which I would plug my usb keyboard and/or a usb hub.
In similar fashion above, run a USB 3.0 cable in the same way to a usb 3.0 module into which I will plug the lead from my Dell monitor to enable the built in usb 3.0 hub.
I purchased two 10m extension ***elsewhere***, both with repeaters built into them. Both leads have good reviews etc.
So yesterday, before putting the final trunking covers back on I thought id test everything to make sure it works.
Keyboard not responding at all from the module but working fine when plugged into computer 10m away. USB 3.0 not responding too.
Checked the voltages and both extensions reading 4.86v so i assume that this is the reason why there is no response.
This morning, just out of curiosity, I took both 10m extension leads and plugged them one at a time into the plug sockets usb charging slots, checked the voltage at the other end 10m away and sure enough both cables reading 5.06v.
So this leads me to believe, rightly or wrongly, that my Mobo is the issue?
I have an i7 2600k cpu with a gigabyte Z77x UP7 mobo, radeon hd 7950 gfx and a seasonic 1000w psu.
It was overclocked to 4.5 ghz @ 1.23v but I reset everything to defaults yesterday to start afresh.
I have 5 fans running @ abut 60%, 1 water pump, 2 ssds running on the computer.

Id be very grateful for some options from those of you a bit more knowledgeable about these things. The unit cannot really be moved closer to the desk because of the configuration of the room.

Thanks

 

[Armageus]

The only other option I can think of would be USB over CAT5 adapters, which will work up to 100m. The downside being they generally only support 1 port (no hubs), and are hideously expensive for what they are.

Surely if you have a desk there in the first place, then there must be some room for a PC? Even if it means downsizing from an atx tower to micro atx or itx sized machine? It must be easier to solve the location limitations than bypass technical limitations.

 

[OLDPHART]

What you need is a USB 2.0 Active Extension Cable helps to boost the signal you can get them upto 30m, as the signal degrades after about 5m.

 

[Tealc]

You'd expect things to work ok at 4.86v. Was this measured with keyboard attached or with no load.

Does keyboard have lights or something?

 

[Rroff]

Can't remember the exact ranges off the top of my head but USB devices are supposed to be tolerant to 4.7-5.2v or something like that so shouldn't be a problem - it could be the differential signalling is being attenuated too much however.

 

[Abz Hussain]

Ok problem has been solved im glad to report.
Tealc i got 4.8v with nothing attached, just used a usb cable i had lying about and stripped it bare and took voltages from that. At that voltage the keyboard did work but only sporadically.
USB 2.0 and USB 3.0 Y splitter cables are being used, simple things costing a few quid each from 'other' retailers have done the trick. now getting 5.06 - 5.16v on both leads (both of which are active leads btw). Keyboard working fine, monitors usb 3.0 hub up and running.
Thanks all

 

[Tealc]

Glad you got it working.